The future of the heating boiler

If you buy a new gas boiler today, the boiler will probably be able to be used for its entire lifetime i.e. 10 to 15 years.

After gas boilers have been phased out, you will be able to heat your home via two main methods, either a heat pump or a boiler that utilises hydrogen gas (at least partly). 

However, the reality is that most UK homes use gas boilers for heating and the expense and viability of replacing all of them with solar and heat pumps is not considered achievable by many observers.

Due to this, hydrogen-ready boilers are seen as the most viable solution, since they can make use of the existing infrastructure, engineers and their price point will likely remain competitive.


The transition to hydrogen 

The transition to hydrogen gas is a moving picture, so the exact timelines and dates of when 100% hydrogen boilers, or hydrogen gas are going to be available are unknown.

However, what is clear is that it is going to be a step-by-step transition that will happen over many years.

The good news is that boiler manufacturers have already started to develop hydrogen ready boiler prototypes and have made it clear that their intention is to price them at a similar rate as current gas boilers. 


This is how the transition to hydrogen is likely to take place over the coming decades: 

Phase 1 - New generation of hydrogen-ready boilers.

Boiler manufacturers will release new hydrogen-ready boilers that are able to accept a combination of gases, including hydrogen. It is assumed that these will be able to be easily modified to accept 100% hydrogen too. It's assumed that these will be available from 2025 onwards.


Phase 2 - New hydrogen gas blend will be rolled out using the existing gas network. 

Currently, there are several projects underway to test the viability of utilising hydrogen gas in the existing network. Initially, this will probably be a blend and not 100% hydrogen.

Thankfully, all new Heatable boilers are able to accept this new 20% blend. This new blend is expected to be rolled out using the existing grid sometime after 2028.


Phase 3 - All homes will be using 100% hydrogen gas boilers. 

The ultimate goal is to have every home in the UK using a 100% hydrogen boiler, that is able to accept pure hydrogen gas. However, this probably won't happen for several decades. 


There remain several barriers to the adoption of low carbon heat and a recent report by the Environmental Audit Committee (EAC) found that it will take over 700 years for the UK to make the transition at its current speed.

Additionally, the Committee on Climate Change (CCC) has estimated that it would cost an average of £26,000 to switch each UK home to a low-carbon heating system.


One potential solution to these barriers is hydrogen fuel, which takes advantage of the current gas infrastructure, which is connected to 8 in 10 homes. Therefore, many industry commentators assert that it’s much more practical to change the fuel instead of the heating system in every home. 

When hydrogen is burned it produces only vapour and no carbon dioxide, so the feasibility of delivering it into homes via the gas network is currently under review by the EAC and CCC.

It’s thought that hydrogen-ready boilers will be rolled out in the coming years, likely from 2025 and beyond, to coincide with the proposed gas boiler ban in new build properties.

The major advantage of a hydrogen-ready boiler is that it can continue to use natural gas until hydrogen gas is available. This will allow the whole country to transition to the low carbon alternative in a strategic way and with almost no disruption to home heating. 


So, why does hydrogen receive so much positive attention?

    •       Emissions contain zero carbon 
Fossil fuels such as coal, oil and gas are all high-carbon fuels that emit carbon dioxide when burned. This is a leading cause of global warming. Hydrogen on the other hand, only produces water, with no carbon dioxide.

    •       Existing Gas infrastructure can be used 
One of the biggest benefits of hydrogen is that it only means changing to fuel supply, so it is much easier and quicker to roll out nationwide. It also avoids the costs and learning curve of households adopting completely new heating systems.

    •       Hydrogen is more efficient than Gas 
There is equal energy in 1kg of hydrogen as there is in 2.8kg of gas that means you can heat homes just as well but use less fuel in the process. 


Disadvantages of hydrogen boilers 

Unfortunately, there are some concerns about the feasibility of hydrogen heating, but this is currently being reviewed by the EAC and CCC.

    •       Hydrogen is not cheap to produce 

    •       Currently, there are two leading methods of hydrogen production: electrolysis or Steam Methane Reforming (SMR).

    •       Electrolysis works by splitting water molecules into two separate hydrogen molecules with the use of a high voltage current. When the electricity used is generated using renewable energy, this is the most eco-friendly method of producing hydrogen.

    •       The second leading method is Steam Methane Reforming which is the method of reacting steam with methane. A by-product of producing hydrogen this way is a carbon by-product. Although it isn’t all negative, the carbon produced can be captured before it’s released into the atmosphere.

    •       Right now, both hydrogen production methods are expensive and so are not viable for the mass market where megatons of hydrogen will be required to provide nationwide supply.

    •       Hydrogen is flammable 
Gas is flammable, but hydrogen is arguably even more flammable due to its energy storage, however, it also doesn’t have a smell, so detectors are an essential part of their use to ensure safety is maintained.

    •       Storage isn’t easy 
Hydrogen isn’t as heavy as natural gas and so it is much more difficult to store and transport. In order to achieve adequate conditions, it needs to be turned into a liquid and stored at a low temperature.

    •       Hydrogen may require major changes to the gas infrastructure 


Many of the hydrogen research projects underway are going to be investigating key concerns and looking for ways to address them to help improve the feasibility of a nationwide rollout using the existing infrastructure. 

This may include some major changes to the current gas infrastructure. For example, electronics must be explosion-proof, since hydrogen essentially burns "like an explosion”.

Additionally, under certain conditions, hydrogen can cause embrittlement to pipework, meaning servicing may need to be carried out more often than with natural gas. 

HyDeploy is a research project being carried out at Keele University, Staffordshire and is testing the viability of using a natural gas and hydrogen mixture on the current network. Specifically, they are testing a 20:80 blend which would mean no substantial changes would need to be made to boilers or the installation process. 

A 20:80 blend is planned to be rolled out from 2025. As of 2020, the project is under review by the Health and Safety Executive (HSE). 

Hy4Heat is a project researching the viability of a complete hydrogen network. 

In 2020, the project released extremely promising results. A key part of the project was looking at how appliances can be used in a safe manner, as with natural gas, safety is a major concern. In addition, there are slight differences between hydrogen and natural gas, such as smell and visibility and so ensuring gas installers are well trained is also an essential part of the research. 

See our Links page for useful Ipswich Borough (and other) links.

Note: Ipswich Building Preservation Trust isn’t able to give direct advice, but aims to start a conversation, inform people of current ideas with arguments for and against.